Water heater control system with thermal retarder



April 10, 1945. c. M. OSTERHELD WATER HEATER CONTROL SYSTEM WITH THERMAL1' RETARDER Filed Feb. 21, 1944 2 Sheets-Sheet 1 INVENTOR CZ ARk/W 0sTE/ -PHELD BY ATTORNEY Patented Apr. 10,1945

- UNITED T TES PATENT OFFICE v WATER HEATER CONTROL'S YSTEM THERMALRETARDER Clark Osterheld, Stoughton,

MoGraw Electric Com ration of Delaware w assignor to Dany, Elgin, 111.,a corpo- Application FebmtYZl, 1944, Serial No. 523,322

14 Claims.

* electric heater on a hot water tank in case of withdrawal of arelatively large quantity-of hot water from the tank and to causeenergization of the electric heater with an adiustably predeterminedtime period of delay in case of withdrawal of a relatively smallquantity of hot water from the tank. I

Another object of my invention is to provide a control system for anelectric heater one. hot

water tank that shall be efiective to cause deenergization of theelectric heater when substantially all of the water in the tank is hot.

In the drawings,

Figure 1 .is a vertical sectional view'of an ordinary domestic hotwatertank showing schematically the positions of the thermal retarderswitch unit, of the lower thermal heater control switch, and 'of theheater,

Fig. 2 is a diagram of electric circuits including an off-peak timeswitch, a thermal retarder switch unit, and a thermal heater controlswitch shown in the positions they will occupy when the upper portion ofthe tank is full of hot' water and the lower portion of the tank is fullduring an on-peak period,

Fig. 3 is a top plan view of the thermal retarder shown in Fig. 4,

Fig.4 is a vertical sectional view on the .line

4-4 of Fig. 3, the position oi the contacts and of the electricconducting fluid being those occupied when the thermal retarder subjectto cold water, I

Fig. 5 is af ront view 01' the parts shown in Fi 4.

Fig. 6 is a fragmentary view of Fig. 4 showing switch a unit is theposition 01 the electric conducting fluid when the thermal retarder lssubject to hot water. Reterringnrst to Fig. 1 o! the drawings, I havethere shown a usual domestic hot water tank H which comprises a lowercold water inlet pipe IS, an upper hot water outlet pipe I5, and whichhas a mass 0! heat insulation l1 therearound, which of cold water tunnel23. All of these details are now well single electric heater latter isheld in proper operative position on tank H as by an outer casing l8.

I provide-preferably, but not necessarily, 9.

2| which maybe of the clamp-on'type and which may be located in a knownin the art. and constitute no part of my present invention. 4

I provide a lower thermal heater control switch 25 which comprises atube 21 having a closed inner end and having its ope'n outer end securedin a fluid tight manner in an opening in tank H near'to the lower'end oithe tank. 'An expansion rod'ZQ'is positioned in the tube 21 and isadapted to engage with and be disengaged from a lug 3| ofelectric-insulating material secured to the free end of a resilientcontact arm 33, which is adapted to engage with and be disengaged from asubstantially'rigidcontact arm 35. The two contact arms may be supportedby two blocks 31 of electric-insulating material. It is to be noted thatI have shown this thermal switch schematically only and any otherstructure effectiv for the same purpose. may be utilized. When tube 21is surrounded by cold water, having a temperature of 70 F., the lengthof rod 29 will be such that it isout of engagement with lug 3| so thatthe two contact arms are in engagement with each other, and when'tube 21is subject to hot water having a temperature on the order of 150 F., thelength of rod 29 is such that the two con- 1 tact arms will be out ofengagement with each other. The thermal switch 25 may be located in anopening 39, in outer casing l9, which may be closed by a cover 4|.

A thermal retarder heater control switch unit designated by numeral 43islocated'in heat re ceiving relation on tank H, and while I may 10-cate it in any position intermediate the ends of the tank, I preferablylocate it at substantially mid-height of the tank in an opening I! inthe heat-insulating mass H, which opening may be closed by a cover 41. j

Referring now to Figs. 3 to 6 inclusive, I have there shown the detailsof my invention relating to a thermal retarder heater control switchunit 43. I provide a supporting block-l9 of a suitable heat-conductingmaterial, the inner surface of which is of arcuate shape sothat ltwlllcorrespond withthe outer arcuate surface of tank H. I may secure support49 inits proper operative 'positionon tank H as by welding seam 5|. A-

heat-conducting member 53 has its inner surl'ace such as to correspondwith the outer suriace of supporting block It, the two members beingheld as by means of a pair of short machine screws 55 extending throughlugs 67 on member 53. Member 53 is provided with a central openingBctherein, which opening is adapted to receive one end portion Bl ofamember 68 of substantially U-shape, which is made of a suitableelectrio non-conducting material and is provided with a second endportion 65 in addition to the first end portion 38, which 59 in block53;

A block 6! of heat-insulating material is provided with a centralopening 39 extending therethrough from top to ottom thereof, and thesecond end portion 65 of the member d3 of U-shape is adapted to bepositioned in opening 69. Any

1 suitable or desired means may be providedior securing block 5? inproper operative position latter fits in the opening" or over, I mayprovide means for varying this,

motor 95 having a worm at on its rotor' shaft. 4

This worm or is adapted to mesh with and drive against and relative toblock 53. The size oi opening Ed is slightly greater than that of theoutside dimension of end portion 58. and a small heating coil ii isadapted to iit between the outer surface of end portion 65 and the innersurface of opening 63. The'terminals of heating coil it may be securedto contact terminals 73 and i6 secured to the iront surface of block$71. A cover member ll may be provided for opening 69.

I provide a mass of fluid electric-conducting material 19, whichmaterial is adapted to be pcsl= tioned in the lower porbon of thetubular member 63 and preferably the of the tube at the in= termediateportion is made smaller than the end portions thereof. I provide a pairof spaced con tact members 83 and, 33, member 38 being adapted toproject through the wall of the upper left hand end portion 01 theintermediate part of tube 63, while the member 33 may extend through thelowermost part of the intermediate portionco'f tube 63. The end portion6! is filled with heat-vaporizable material which will vaporize at orabout the temperature of hot water in the tank so that the lever of themass of electrlc-conductingmaterial 19 in the left hamd portion of theintermediate part of the tube will be forced downwardly intosubstantially the position shownin Fig. 6 .01 the drawings. The-portion65 of the tube 63 is filled with heat-vaporizable material which willvaporize 'at or about a temperature of 300 F., with the result that thelevel of the' electric-conducting fluid 19 will be forced downwardlyfrom the position shown in Fig. 6 to. the position shown in Fig. 4. Thusin case the heating coil II is not energized or has been energized "forless than a predetermined period of time necessary to raise thetemperature of thematerial in portion 65 to a value approach ing 300F;,- and the left hand portion 81 is sub iect to a temperature on theorder oi 150 F., the

' circuit controlled by the two contact members 18! and 83 will beopened. In case the tempera= ture of both'portions El and 8571s on theorder of ordinary room temperature, the'circuit controlled by the twocontacts 8| and 83 will be'closed, which will also be the case if thetemperature of portion BI is on the order of 150 F.1and the temperatureof the righthand portion 65 is on the order or 300". F. 1 The twocontacts 8! and 83 may be connected to contact terminals 85 and 8'!suitably secured tofthe front surface of block 61. The lower. or'intermediate portion of member 8 may be encased in a block 890iheat-insulating'material'. v While it is usually'unnecessary to providea worm gear 99, whichgear is positioned on the end of a shaft Edi, whichshaft has a cam disc ltd secured on the other end. The general design,construction, and operation of the structure thus far described is thatearn disc ltd is rotated through one complete turn in twenty-iour'hoursby the continuously operative motor 95. The cam disc 33 is provided witha reduced peripheral portion E35 having a larger radius, the peripheralextent or portion 895 being substantially equal to that of an oft-peakperiod. Such cit-peak period is considered by many utilities to start at12 midnight and to end at 6 a. m. so that the perlph- V erai extent ofportion we will be 90 or one quarter of the total peripheral of com discW3.

- I provide a circuit switch comprising a resilient contact arm illll,having a lug its of electric-insulating material on its outer free end,this log I03 being normally adapted to engage the surface oi cam discm3. -When the lug E09 rests upon the portion I83 of cam disc 33, the armllll will be moved in a clockwise direction and into engagement with arigid contact arm HI. The two arms I0! and Hi may be held in theirproper operative positions relative to each other and 40 to cam disc 183as by blocks H3 of electric-insulating material. The designandconstruction of the time controlled switch is such that the switch isheld'in closed position during any oil-peak period, which is generallyduring late night hours,

While during the daytime'and during the early night hours this switch isopen.

I provide a pair of supply circuit conductors H5 and Ill, conductor H5being connected to,

rigid contact arm Hi. Resilient contact arm IN is connected by conductorUs to contact member ti of the thermal retarder switch unit. The secondcontact 83 is connected by a conductor lZi-to one terminal of electricheater 2!, the other terminal of which is connected to rigid contact arm35 and by a conductor I23 to one terminal of adjustable rheostat 9 l Theother terminal of rheostatsl is connected by a conductor, I25 with oneterminal of heating coil H, the other terminal of which is connected bya conductor I21 to contact arm llll. Contact arm 33 is connected by aconductor I29 to the second supply circuit conductor H1. Motor 95 isconnected by conductors l 3l "aim i33 with supply circuit conductors H5and Let it now be assumed that the tank is first filled with cold waterduring an ofl-peak period so that the circuit switch controlled by thetimer is in closed position; The subjectionv of end portion 6| of thethermal retarder heatercontrol switch unit to cold water and the endportion 65 to room temperature results in the closure .of thecircuitcomprising contacts 8| and 83 and means tor-varyingl'the lengthof timerequired by heati'ngcoil ll to cause rise of temperature of .endportion 85 to a value onjthe order M1300? F.

' Fig; 4' of the drawings.

of cold water causes 'cuit may be traced as follows: from supply circuitconductor Ili through engaged contact arms III and I01, conductor III,contact ll, electric-conducting fluid Il, contact 83, contactor I 2I,heater II, conductor I25, rheostat 9i, conductor I23,

2I, engaged contact arms 35 and I3, and through conductor I29 to thesecond supply circuit conductor I I1. The heating coil 'II will also beener gized, which circuit may be traced as follows: from supply circuitII! through engaged contact arms III and "I1, conductor I2'I. heatingcoil engaged contact arms '35 and 33, and through conductor I29 to thesecond-supply circuit con- .ductor II'I.

Heating of the second portion '6 of the thermal retarder unit to amaximum temperature on the order of 300 F. will beeflected in a periodof time on the order of five hours or more or less in accordance withthe adjustment of rheostat 9|. Whenstarting with a tahk filled with coldwater, the temperature of the water will be substantially uniform fromtop to bottom of the tank, and this temperature will increase with lapseof time until the temperature of all of the water in the tank hasreachedthe desired maximum, which as stated hereinbefoie. may beconsidered-to be on the order of 150 F. For illustrative purposes. itmay be mentioned that the total length of time required to heat all ofthe water in the tank is on the order of six hours. Theelectric-conducting fluid I! will therefore remain in substantially thepodtion shown in Fig. 4 so that the energization of heater 2I will notbe interruptedv until all of the water'in the tank is hot. when thiscondition obtains, the

lower thermal switch 2! will be effective to interrupt the energizationor heater 2I, and the heating coil 1| will also be deenergized with the'resulting'cooling of portion G5, which permits -the electric-conductingfluid lfto move to the position shown in Fig. 6.

Let it now be assumed that substantially all of the water in-the tankwas hotby the time that the circuit switch was opened at the end of anoiI-peak period. Let it be further assumed that only a, relatively smallquantity of water is withdrawmduring the daylight hours and during theearly night hours so) that only the lower thermal heaieracontrolswitch?" is subject to,

cold water just before the start of an oil-peak period. As soon ascontactar'ms Ill and III are-in engagement at the start of an ofl-peakperiod, 'energization of the low-wattage heating coil'II will be startedand will continue until the temperature -of portion II has been raisedto a valueon the order of 300' E, with the result that theelectric-conducting'fluid I! will be moved from the position shown inFig. 8 back to the position shownin Fig. 4 thereof, with-mg result thatenergization of heater-[2| will start and continue for the rest of theoil-peak period.

- In case such an amount oi hot water was withdrawn from'the. tankduring daylight hours and during early night hours that the thermalretarder switch unit was also subject to cold water,

the position of the electric conducting fluid I9.

would be that shown in Fig. 4' of the drawings.

If this condition occurred early-in the evening, the energiaing circuitheater 2| would still beopen and would not be closed until enagement ofthe 7 er controlled contact arms III andIII at thee ofan cit-peakperiod.

asrarbe Energization of the heater 2I would therefore begin at the startof an off-peak period and continue until all of the water in the tank ishot,

when the lower thermal switch 25 will open the circuit.

' In case-the time controlled switch is not provided, the same commentsas made hereinbefore will apply, with the exception that energization ofheater 2i will begin immediately upon subjection of the thermal retarderheater control "switch unit to cold water or will begin a predeterminedtime period of delay after subjection of the lower thermal heatercontrol switch to cold water.

Various modifications may be made in the device and system embodying myinvention without departing from the spirit and's'cope thereof, and allsuch modifications coming clearly within the appended claims shall beconsidered a part 20 of my invention.

I claim as my invention: 1. A water heatercontrol system for a hot watertank having an electric heater and a thermal retarder heater controlswitch unit compris-- 7 tive end portions, 9, heat-conductive enclosurefor one of said end portions adapted to be secured in heat-receivingrelation to a hot water tank intermediate the ends thereof, aheat-insulating enclosure for the other of said end portions, anelectric heating coil around said other'end portion and a pairofelectric contact members in said intermediate portion of said tubeadapted to be connected in series circuit with said-electric heater,said contact members being electrically connected by saidelectric-conducting fluid when the temperatures of said end portions'ofthe tube are at substantially ordinary room temperature. 2-. A waterheater control system for a hot water tank having an electric heater anda thermal retarder switch unit comprising a closed tube'of U-shapehaving an electric-conducting fluid in it m rmediate portion andthermally-expansiheat conductive enclosureior one of said end portionsadapted to be secured in heat-receiving relation to shot water tankintermediate th ends thereof, a heatinsulating enclosure for the otherof said end portions, an electric heating coil around said other endportions, and a pair'of syste m one hot water tank having an electricheater an a thermal reta'rder heater control switch unit'comprising aclosed tube of U-shape having an electric-conducting fluid in itsintermediate portion and thermally-expansible substances in therespective end portions, a heat-conductive enclosure for one 01 said endportions adapted to besecured in heat I receiving relation to a hotwater tank intermediate the ends. thereof, a heat-insulating enclosurefor the other of said ends portions, an. electric heating coil forsaidother end portion and a pair of electric contact members in saidintermediate portion of said tube adapted tobe connected in seriescircuit with said electric heater, said contact members'beingelectrically connected by said electricble su stances in the respectiveend portions, a-

conducting fluid when the first end portion of said mediate the endsthereof, a heat-insulating en closure for the second end portion, anelectric heating coil around said second end portion and a pair ofelectric contact members in said intermediate portion of said tubeadapted to be conneoted in series circuit with said electric heater,said contact members being electrically connected by saidelectric-conducting fluid when the first end portion of said tube issubject to the tem- 'perature of cold water in the tank and the secndportion of the tube is at substantially ordinary room temperature andsaid contact members being electrically disconnected by saidelectricconducting fluid when enough water in the tank has been heatedto apredetermined high temperature to subject said first end portion tothe temperature of said heatedlwater and the temperature of said secondend portion i at substantially ordinary room value.

* 5. A water heater control system for a hot water tank having anelectric heater and a thermal retarder heater control switch unitcomprising a closed tube or U-shape having an electric-com ducting fluidin its, intermediate portion and thermally-expansible substances in therespective end portions, a heat-conductive enclosure for one of said endportions adapted to be secured in heatreceiving relation to a hot watertank' interported by said heat-conductive enclosure, an electric heatingcoil for said other end portion and a pair of spaced contact members insaid inter-'- mediate portion adapteol to he -connected in seriescircuit with saidelectric heater, said contact members beingelectrically connected by said electrically-conducting fluid when thetemperatures of both said end portions are at substantially the same lowvalue and when the temperatures of both end portions are atpredetermined relatively values. I V. 7. A thermal retarder switch unitfor controlling the energization of an electric heater-for a hot watertank, comprising 'a'closed tube of electric insulating material and ofsubstantially ushape having an electric-conducting fluid in itsintermediate portion and thermally-expble substances in the respectiveend portions, 2. heatconductive enclosure for one of said endportionsadapted to be secured in good heat-conducting relation tothe-outside of a hot water tank intermediate the ends thereof, aheat-insulating enclosure for the other end portion suppogedby saidheat-conductive enclosure, an electri heating coil around said other-endportion and pair of spaced contact members in said intermediate portionadapted to be connected in series circuit with said electric heater,saidcontact members being electrically disconnected by saidelectricconducting fluid when said one. end portlon'is subject to thetemperature of hotv water in the tank and said other end portion is atsubstantially ordinary room temperature. I o 8. A thermal retarderswitch unit for controlling the energization of an electric heater for ahot water tank, comprising a closed tube oi elec-' tric insulat ngmaterial and of substantially U- shape having an electric-conductingfluid in its mediate the ends thereof, a heat-insulating enclosure forthe second end portion, an electric heating coil for said second endportion and a pair of electric contact members in said intermediateportion of said tube adapted to be connected in series circuit with saidelectric heater, said contact members being electrically connected bysaid electric-conducting fluid when the first end portion of said tubeis subject to the temperature of cold water in the tank and said secondportion of the tube is at substantially ordinary room temperature andsaid contact members being electrically disconnected by saidelectric-conducting .fluid when said first end portion of the thermalretarder switch unit is subject to hot water and the temperature of saidsecond end portion is at substantially ordinary room value and saidcontact members being adapted to be electrically connected with apredetermined time period of intermediate portion andthermally-expansible substances in the respective end portions, a heat-Y conductive enclosure for one of'said end portions adapted to besecured in good heat-conducting relation to the outside of a hot watertank intermediate the ends thereof, a heat-insulating enclosure for theother end portion supported by said heat-conducting enclosure anelectric heat- Y I ing coil around said other end portion and a pair ofspaced contact members in said intermediate portion adapted to beconnected in seriescircuit with said electric heater, said contactmembers being electrically disconnected by said electricconductingfluidwhen said one end portion is tank and the heating coil tor the other endpordelay when said first end portion is subject to hot water in. thetank and the heating coil for said second end portion has beenenergized.

6. A thermal retarder heater control switch unit for controlling theenergiiation of anelectric heater for a hot water tank, comprising aclosed tube of electric-insulating material and of substantiallyill-shape having an electric-com ducting fluid in its intermediateportion and thermal y-expansible substances in the respective endportions, a heat-conductive enclosure for one or said end portionsadapted to be secured in good heat-conducting relation to the outside ofa hot water tank intermediate the'ends thereof, a heatlnsulatingenclosure for the other end portion supsubiectto the temperature of'hotwater in the tion has been energized for less than a prede terminedlength of time.

9. A water heater control system for a. domestic hot water tank subjectto withdrawals of hot water during a twenty-four hour day, comprising anelectric heater to be'en'etgized from an electric supplycircuithavingreduced demands for energy during-late night hours,- a

thermally-responsive heater control switch sub-. ject to tank watertemperatur'eat the lower end portion of the tank anda thermal retarderheater control switch unit adapted to be mounted one tank intermediateits ends and including a closed tube of electric-insulating materialandof U- shape having an electric-conducting fluid in its intermediateportion,'.thermally-expansible substances in the respective endportions, a heatconductingenclosure for one-oi said end portions"adapted to be secured in'good heat-conducting engagement with theoutside. or a tank intermediate the ends thereof, a heat insulatinoenclosure for the other end portiom'a heating coil around the other endportion and a, pair of spaced contact members in said intermediateportion adapted to be connected in series circuit with said electricheater, a continuously operative timer and a heater circuit switchadapted to be closed by said timer during said period of reduced demand,all of said heater control switches being jointly effective to causeenergization of said elec tric heater simultaneously with the closing ofsaid circuit switch in case the thermal retarder is subject tocold waterin the tank.

10. A water heater control system fora domestic hot water tank subjectto withdrawals of hot water during a twenty-four hour day, comprising anelectric heater adapted to be energized from an electric supply circuithaving reduced demands for energy during late night hours, athermally-responsive heater control switch subject to tank watertemperature at the lower end portion of the tank and a thermal retarderheater control switch unit adapted to be mounted on a tank intermediatethe ends thereof and including a closed tube of electric-insulatingmaterial and of U-shape having an electric-conducting fluid in itsintermediate portion, thermally-expansible substances in the respectiveend portions, a heatconducting enclosure for one 'of said end portionsadapted to be secured in. good heat-conducting engagement to a tankintermediate the ends thereof, a heat-insulating enclosure for the otherend portion, a heating coil for the other end portion and a pair ofspaced contact members in said intermediate portion adapted to beconnected in series circuit with said electric heater, a continuouslyoperative timer and a heater circuit switch adapted to be closed by saidtimer during said period of reduced demand, all of said heater controlswitches being jointly effective to cause energization of said electricheater with a predetermined time delay period after closing of saidcircuit switch by said timer in case the 5118113181 retarder is subjectto hot water in the ten 11. A water heater control system for a domestichot water tank subject to withdrawals of hot water during a twenty-fourhour day, comprising an electric heater adapted to be energized from anelectric supply circuit having reduced demands for energy during latenight hours, a. thermally-responsive heater control switch subject totank water temperature at the lower end portion of the tank and athermal retarder heater control switch unit adapted to be mounted on atank intermediate the ends thereof and including a closed tube ofelectric-insulating material and of U-shape having anelectric-conducting fiuidin its intermediate portion,thermally-expansible substances in the respective end portions, aheatconducting enclosure as one of said end portions adapted to besecured in good heat-conducting engagement with the outside or a tankintertimer in case the thermal retarder is subject to hot water in thetank and said thermally-responsive heater control switch being effectiveto cause deenergization of said heater when the tank is full of hotwater.

12. An ofi-peak water heating system for a hot water tank having anelectric heater, comprising a continuously operative timer, a firstheater control switch adapted to be moved into and held in closedposition by said timer during an onpeak period, a second thermal heatercontrol switch in series circuit with said timer controlled switch andsubject to tank water temperature adjacent to the lower portion of thetank and adapted to be moved into closed position when subject to coldwater, a third heater control switch in series circuit with said firstand second switches and said heater, and means to cause closing of saidthird switch with a time delay period after start of an ofi-peak periodin case said second switch only is subject to cold water, said meanscomprising a closed tube of electricinsulating material and of U-shapehaving an electric-conducting fluid in its intermediate portion andthermally-expansible substances in its end portions, a heat-conductingenclosure for one of said end portions adapted to be mounted in goodheat-conducting engagement on a tank intermediate the ends thereof, aheat-insulating enclosure for the other end portion, a heating coil forsaid other end portion controlled by said time switch and said secondswitch to be energized of an oil-peak period and a pair of contactmembers in said intermediate portion adapted to be connected by saidfluid after a time delay period with attendant energization of theelectric heater.

13. An off-speak water heating system for a hot water tank having anelectric heater, comprising a continuously operative timer, a firstheater control switch adapted to be moved into and held in closedposition by said timer during an oilpeak period, a second thermal heatercontrol switch in series circuitwith said timer controlled switch whensubject to tank water temperature adjacent to thelower portion of thetank and adapted to be moved into closed position when subject to coldwater, a third heater control switch in series circuit with said firstand second switches and said heater, a means to cause closing of saidthird switch immediately after start of an off-peak period in case saidsecond and third switches are subject to cold water, said meanscomprising a closed tube of electric-insulating material and of U-shapehaving an electric-conducting fluid in its intermediate portion andthermally-expansible substances in'its end mediate the ends thereof aheat-insulating enclosure for the other end portion, a heating coil {orsaid other end portion and a pair of spaced contact members in saidintermediate portion adapted to be connected in series circuit with saidelectric heater, a continuously operative 'timer" and a heatercircuit-switch adapted to be closed by said timer during said period ofreduced demand, all of said heater control switches being Jointlyeffective to cause energization of said electrlc heater with apredetermined period or time delay after closing oi said circuit switchby said portions, a heat-conducting enclosure for one of said endportions adapted to be securedin good heat-receiving engagement on atank intermediate the ends thereof, a heat-insulating enclosure for theother end portion, a heatingcoil for heating said otherend portion andcontrolled jointly by said second, switch and said timer switch to beenergized at the start of an elf-peak period and a pair of contactmembers in the intermediate portion adapted to be connected by saidfluid to cause energization of said heater upon start of an onpeakperiod.

14; A water heating system as set forth in claim 13 in which said secondswitch is adapted to open and cause deenergization of said heater whensubstantially all 01' the water in the tank is hot.

' CLARK M. OS'I'ElRI-IELD.

